A number of attempts have been made to sense the condition of surfaces for vehicular travel, such as roadways and aircraft runways, during changing or adverse weather conditions. For example, existing warning systems on road vehicles such as cars and trucks may detect basic moisture and temperature factors. Some examples of such systems are disclosed in U.S. Pat. Nos. 4,492,952 and 4,678,056. One particular system, disclosed in U.S. Pat. No. 5,216,476, employs an infrared sensor which is mounted on the exterior of the vehicle and sends a signal to a microprocessor which then can display the temperature of the road surface.
Alternately, in maintenance applications, conductivity, temperature and other sensors may be placed either in a road surface or adjacent the road to monitor the temperature of the road surface and/or monitor whether there is ice forming on the surface. This information is fed to a center for control and dispatch of trucks to apply salt, sand or other deicing mixtures. At airports, these systems may warn maintenance crews that the runways need to be treated or alert staff that deicing procedures need to be implemented. Some conventional treatment systems have a supply of chemicals and pumps beside the roadway to automatically spray the road when triggered by a sensor. Alternately, deicing or other conditioning treatments (such as friction enhancing treatments) may be applied from surface conditioning vehicles, which often include material spreaders.
Surface conditioning vehicles with material spreaders may also be used to provide pesticide and fertilizer spreaders in agricultural applications. In either agricultural or roadway/runway maintenance applications, it is often desirable to spread multiple treatment materials upon the surface, simultaneously. In many instances, each material has its own delivery system, and parameters for application of each material, such as amount and spread width, must be independently set by an operator. In the event the surface condition changes, for example due to change in the width or composition of the surface, the operator must modify the application of each treatment material separately.